Conventionally, a rotor of a permanent magnet embedded motor configured as described below has been proposed. That is, the rotor of a permanent magnet embedded motor includes a rotor iron core that is formed by stacking a plurality of magnetic steel sheets, permanent-magnet insertion holes that are formed in a shaft direction of this rotor iron core and that are formed in regions corresponding to each side of a substantially regular polygon that centers on a shaft center, permanent magnets respectively inserted into the permanent-magnet insertion holes, a plurality of slits that are formed in an outer-peripheral side iron core portion of each of the permanent-magnet insertion holes and arranged with a gap from one another along each permanent-magnet insertion hole, and an outer thin portion that is provided between radially outer ends of these slits and the outer circumference of the rotor iron core and has a radial width that becomes greater as the outer thin portion comes closer to interpolar portions from the center of magnetic poles of each of the permanent magnets. With this configuration, the rotor of a permanent magnet embedded motor can reduce the harmonic components of magnetic-flux density waveforms in the interpolar portions, and can reduce the harmonics of an inductive voltage and cogging torque (see, for example, Patent Literature 1).